Selector switch



June 27, 1939. c. N. i-HCKMAN SELECTOR SWITCH Filed Aug. 4, 1938 2Sheetsq'iheet 1 FIG. 3

INVENTOR CMH/CKMAN 63%. M

ATTORNEY June 27, 1939. Q KM N 2,164,034

SELECTOR SWITCH Filed Aug. 4, 1958 2 Sheets-Sheet 2 INVENTOR C. IV.H/CKMAN ATTORNEK Patented June 27, 1939 UNITED STATES PATENT OFFICESELECTOR SWITCH York Application August 4, 1938, Serial No. 222,974

14 Claims.

This invention relates to selector switches for establishing connectionsin machine switching telephone systems and more particularly to a brushcarriage for a selector switch of the type having access to panel banksof terminals.

Panel type selector switch frames are provided with one or more flat orpanel banks of terminals with which the brush sets of a plurality ofselector switches cooperate. These banks may be mounted either one aboveanother or sideby-side. In some types of selector switches the brushsets are rigidly mounted on elevator rods which are guided in supportsmounted on the switch frame and in other types they are slidably mountedon guide rods which are rigidly secured at their ends to end members ofthe frame. In either case, due to the extensive area of the bank, theremay be a tendency of the brush supporting rod or the banks to vibratelaterally with respect to each other thereby causing a lateral slidingmovement of the brushes on the terminals of the banks with which theyare engaged. The vibratory movement imparted to the brush rod or to thebank may be due to building vibrations or due to the operation of otherswitches mounted on the same frame. This vi bration, if imparted tobrushes which are included in an established talking circuit, is veryundesirable since it may impose objectionable noise on the speechtransmission circuit. In some types of panel switches the-brushes aredriven at very high speeds thereby increasing the possibility ofintroduction of vibration to the banks through the engagement of thebrushes with bank terminals and through the switch frame.

It is therefore the object of the present inven tion to nullify theefiects of bank vibration by providing a brush carriage which is sofirmly pressed against the face of the terminal banks that it maypartake of any lateral vibratory movement of the face of the banks andas a consequence eliminate any tendency of the brushes to slide in anydirection with respect to the bank terminals.

In accordance with the invention, this object is obtained by mountingthe brushes on a sled which rests on the ends of the terminals of therows of bank terminals with which the switch is assigned to cooperateand is provided with parallelly disposed portions or ribs which enterbetween the edges of adjacent rows of terminals whereby the sled isguided in its movement over the rows of terminals. The sled is arrangedfor movement longitudinally over the rows of terminals and is heldpressed against the, banks by sliders or a roller spring-supported onthe sled which engage against a member secured between the end bracketsof the switch unit and positioned parallel to the face of the banks.

In accordance with one embodiment of the invention, four brush springsare attached to the sled each terminating in a contact shoe, the shoesof the two inner springs serving to engage the edges of the two innerrows of terminals, for example the test and metering terminals, and theshoes of the two outer springs serving to engage the ends of the twoouter rows of terminals, or the tip and ring terminals. The innersprings are so formed as to have flexibility in a directionperpendicular to the edges of the terminals with which their shoesengage and the outer springs are so formed as to have flexibility in adirection perpendicular to the ends of the terminals with which theirshoes engage and thus perpendicular to the face of the banks, wherebythe shoes are forced into solid contact with the terminals. The outersprings having flexibility in a direction at right angles to the face ofthe banks, enable their contact shoes which are included in thecommunication circuit established over the tip and ring terminals of thebanks to move with the banks on any lateral vibratory movement of thebanks thus further insuring that there will be no sliding movement ofthe contact shoes on such terminals which might introduce noise into thecommunication circuit.

For a more complete understanding of the invention, reference may be hadto the following detailed description taken in connection with theaccompanying drawings in which:

Fig. 1 is a perspective view of a brush carriage constructed inaccordance with the invention;

Fig. 2 is a side elevational view of the brush carriage;

Fig. 3 is a top end view of the brush carriage with portions thereofomitted for clarity of disclosure;

Fig. 4 is a detail of one end of the brush carriage sled showing themanner in which the sled is attached to the supporting frame;

Fig. 5 is a cross-sectional view of the sled showing the manner in whichthe brush spring shoes engage the rows of terminals of terminal sets;

Fig. 6 is a perspective view of one of the inner brush springs;

Fig. '7 is a perspective view of one of the outer brush springs;

Fig. 8 is a side elevational view of a modified form of the brushcarriage;

rows of terminals.

Fig. 9 is a top end view of the brush carriage disclosed in Fig. 8;

Fig. 10 is a rear elevational view of the brush carriage of Fig. 8; and

Fig. 11 is a perspective view of one of the brush springs of Fig. 8.

The brush carriage has been disclosed as of a type particularly adaptedfor use in a selector switch of the character disclosed in theapplication of W. W. Carpenter and R. F. Mallina, Serial No. 213,743,filed June 15, 1938, but it will be apparent that the invention isequally applicable to other well-known types of selector switches.

In accordance with one embodiment of the invention disclosed in Figs. 1to 7, inclusive, the carriage comprises a body portion I of suitableinsulating material having a shoe 2 formed on the upper end thereof anda shoe 3 formed on the lower end thereof. The upper shoe 2 is providedwith two convex outer surfaces 4 from which two parallel guide ribs 5and 6 extend. The lower shoe 3 is similarly provided with a convex outersurface I from which two parallel guide ribs 8 and 9 extend. The bodyportion with its two shoes constitutes a sled which is adapted to bemoved over four rows of bank terminals with the surfaces 4 and I of itsshoes in engagement with the ends of the terminals of the rows and withthe guiding ribs of its shoes guided between the inner edges of the twooutside rows of terminals. The manner in which the upper shoe 2 engagesthe ends of the bank terminals and is guided along the rows of terminalsis best illustrated in Fig. 3.

It will be noted that the convex formation of the surfaces 4 and I ofthe shoes insures that as the shoes move along the rows of terminals theedges of the shoes will not snag on the terminals. The space between theribs 5 and 6 of shoe 2 and between ribs 8 and 9 of shoe 3 is slightlygreater than the combined width of the inner rows of terminals I and I Iand the distance between the outer faces of the ribs and 6 and the ribs8 and 9 is only slightly less than the distance between the inner edgesof the outer rows of terminals I2 and I3 as most clearly disclosed inFig. 3. The outer faces of the ribs are thus enabled to slide over theinner edges of the outer rows of terminals and thereby guide the shoes.along the To prevent snagging on the terminals the outer faces of theribs are made convex as disclosed in Fig. 1.

The body portion I of the sled is secured by bolts I4 to a frame I5havingtwo forwardly extending arms I6 and H, the ends of which areunited at I8. The ends of the frame I5 are provided with ears I9 and 20to which the ends of a tape belt may be attached for moving the brushcarriage along the rows of terminals to which the switch is assigned.The outer end of the upper arm I! of the frame is bent at right anglesand formed with a cylindrical sleeve 2I to which the end of a cable offlexible conductors (not shown) for making connection with the brushsprings mounted on the brush carriage may be secured. For addingrigidity to the upper arm I? of the frame the upper edge thereof isproyided with a rib 22 bent at right angles therefrofi This arm is alsopro-vided with tabs 23 and 24 struck therefrom, and an eyelet 25 engagedtherein for holding the conductors extending from the flexible cable tothe soldering lugs of the brush springs in position.

Secured on the side faces of the body portion I of the sled are fourbrush springs two on each side thereof. The two inner brush springs 26and 2'! are of the type disclosed in Fig. 6, each being of substantiallyrectangular outline and stamped out to form a central supporting section28, a rear arm 29 joined at its mid-portion to the section 28, two endarms 30 and 3! and a front arm 32. The rear arm of the spring is formedwith a soldering lug 33 and the forward arm is provided with a forwardlyextending tab 34 the end of which is bent at right angles to form an ear35 and from which a second car 36 is struck out and bent at right anglesparallel to the ear 36. The ears 35 and 36 serve to support a contactshoe 3'! which is secured therebetween by a rivet. The contact shoe hasa body of insulating material in one face of which a contact member 38is imbedded.

Each of the outer brush springs 39 and 40, one of which is disclosedmost clearly in Fig. '7, comprises a supporting portion 4i having a.soldering lug 42 bent up therefrom at its upper end, a

stiffening rib 43 bent up at right angles along one edge and having itsother edge near the outer end thereof bent at right angles andterminating in a flexible arm M for supporting a contact shoe. The outerend of the arm 54 is formed with two ears 45 and 46 bent at right anglesthereto and parallel with each other between which a contact shoe 41 isriveted. The body of the shoe is of insulating material and one of theears 46 is bent over the outer surface of the shoe to form a contactsurface 48. Springs 26 and 35 are assembled on one side face of the bodyportion I of the sled with an insulating separator 49 disposed betweenthem as best shown in Fig. 5 and the springs 21 and 40 are similarlyassembled on the other side face of the body portion with an insulatingseparator 50 between them. The assembled springs are all clamped inposition by screws 5| which extend through holes in the outer clampingplate 52, the insulating plate 53, spring 39, insulating separator 49,spring 26,

body portion I, spring 21, insulating separator 50,

spring 40, insulating plate 54, into threaded holes in the clampingplate 55. For insulating the springs from the screws the screws may besurrounded in the usual manner by sleeves of insulating material.

Due to the construction of the inner springs 26 and 21, they haveflexibility in a direction at right angles to their planes and aresopretensioned as to tend to force the contact shoes carried therebytoward each other for engagement with the outer edges of the inner rowsof bank terminals I0 and I I as disclosed in Fig. 5 and the arms 44 ofthe two outer springs- 39 and ill have flexibility in a direction atright angles to the face of the banks and are pretensioned to force thecontact shoes carried thereby against the ends of the two outer rows ofbank terminals I3 and I4 as disclosed in Fig. 5.

For maintaining the brush carriage sled in engagement against the endsof the terminals of the rows of the banks with which it is assigned tocooperate, a spring 55 is riveted or otherwise secured at itsmid-portion to the frame I5, each end of the spring being formed withtwo parallel ears 51 and 58 between which is riveted a slider or shoe59. The sliders 59 engage the inner face of a bar 60, the ends of whichare secured to the end brackets of the switch unit in such a manner asto position the bar parallel to the face of the terminal banks. The endsof the spring 55 are pretensionecl to force the sled toward the face ofthe banks.

When, therefore, the brush carriage is moved in either direction by thetape belt secured to the ears I9 and 20, the sled of the brush carriageis held against the ends of the rows of bank terminals by the sliders 59on the ends of spring 56 engaging the inner face of bar 60 and is guidedalong the rows of terminals by the ribs and '6 of shoe 2 and the ribs 8and 9 of shoe 3. Should. the bank vibrate laterally toward the bar 60the whole brush carriage will move laterally with the bank against thetension of the spring 56 and there will be no tendency for the brushshoes carried by the brush springs to slide with respect to theterminals with which they are at the time engaged. Furthermore, sincethe outside springs 39 and 40, through which the talking circuit isestablished, are capable of flexing in the direction of the bankvibration, they further insure that there will be no sliding movementbetween their contact shoes and the tipand ring terminals I3 and I2which might introduce noise into the talking circuit.

In Figs. 8 to 11, inclusive, a further embodiment of the brush carriageis disclosed. In accordance with this embodiment, the carriage comprisesa body portion 6| of suitable insulating material having a shoe 62formed on the upper end thereof and a shoe 63'formed on the lower endthereof. The upper shoe 62 is provided with a convex surface 64 fromwhich two parallel guide ribs 65 and 96 extend. The lower shoe issimilarly provided with convex surfaces 61 from which two parallel guideribs 68 and 69 extend. The body portion with its two shoes constitutes asled which is adapted to be moved over four parallel rows of bankterminals with the surfaces 64 and 61 of its shoes in engagement withthe ends of the terminals of the rows and with the inner surfaces of theribs of both shoes guided by the outer edges of the two inner rows ofterminals and the outer surfaces of the ribs 68 and 69 of the lower shoe53 guided by the inner edges of the two outer rows of terminals. Thesurfaces 64 and 61 of the shoes and the guiding surfaces of the ribs 65,66, 68 and 69 are made convex to insure that the shoes will not snag onthe ends or edges of the terminals as the shoes move along the rows ofterminals.

The body portion 6| of the sled is secured by bolts between ears H and12 bent at right angles from one edge of a supporting frame 13 tooverlie one side face of the body portion BI and other ears struck outof the forwardly extending arms 14 and of the frame and bent to overliethe other side face of the body porto the frame and the outer end of theupper arm 14 is bent at right angles and formed with a cylindricalsleeve 19 to which the end of a cable of flexible conductors may besecured. For adding rigidity to the upper arm I4 the edges of the armare provided with ribs 80 and 8| bent at right angles therefrom. Thisarm is also provided with tabs 32 and 83 struck therefrom which servefor holding in place the conductors extending from the flexible cable tothe soldering lugs of the brush springs.

Secured on the side faces of the upper shoe 3: of the sled are fourdownwardly extending brush springs 84 to 81, inclusive. Each spring issubstantially L-shaped as disclosed most clearly in Fig. 11, andcomprises an upper rectangular supporting portion 88 having elongatedopenings 89 therein through which clamping screws may extend, aforwardly extending soldering lug 90 and a downwardly extending arm 9|.The end of arm 9| is provided with an L-shaped laterally extending ear92 to which is riveted a contact shoe supporting member 93 having itsfree end extending parallel to the face of the brush spring arm 9|.Positioned on the end of the member 93 with one of its surfaces engagedagainst one face of the brush spring arm 9I is a contact shoe having abody portion of insulating material. For its support on the member 93the shoe is provided with a suitable slot through which the member 93extends. The outer face of the shoe is laterally grooved to support acontact member 95, most clearly shown in Fig. 10, the ends of which aresoldered or otherwise secured to the member 93.

The four brush springs are all similar in construction except that thetwo which are secured on one face of the sled shoe 62 have their ears 92bent therefrom in one direction and the two which are mounted on theother face of the sled shoe 62 have their ears 92 bent therefrom in theopposite direction, as most clearly shown in Fig. 9.

Springs 84 and B5 are assembled on one side face of the shoe 62,separated by a metal block 96 and two insulating plates 91 and 98 andthe springs 86 and 81 are similarly assembled on the other face of shoe62 separated by a metal block 99 and two insulating plates I00 and I M.The assembled springs are all clamped in position by screws I02 whichextend through holes in the outer clamping plate I03, insulating plateI04, spring 84, insulating plate 91, block 96, insulating plate 98,spring 85, shoe 62, spring 86, insulating plate I60, block 99,insulating plate IDI, spring 81 and insulating plate I05 into tappedholes in the clamping plate I96. For insulating the springs from thescrews I02, the screws may be surrounded in the usual manner by sleevesof insulating material.

By the provision of the elongated openings 89 in the brush springsthrough which the insulated clamping screws I02 extend, the positions ofthe contact members 95 of the contact shoes of the four brush springswith respect to the terminals I0 to I3, inclusive, of a terminal set maybe accurately adjusted as disclosed in Fig. 10.

For maintaining the brush carriage sled in engagement against the endsof the terminals of the rows of the banks with which it is assigned tocooperate, a U-shaped spring I91 is provided, one arm of which issecured to the frame 13 by rivets I08 and the other arm of whichterminates in two ears I99 and II 9 between which a roller III isrotatably secured by the pivot rivet H2. The roller III engages theinner face of the channel member II 3, the ends of which are secured toplates (not shown) secured to the end brackets of the switch unit insuch a manner as to position the face of the channel member parallel tothe face of the terminal bank. The roller end of spring I01 is sopretensioned that with the roller engaged on the face of the channelmember N3, the sled is firmly forced against the face of the bank. Thechannel member I I3 also serves as a guide for the depending loop of theflexible cable (not shown) one end of which is secured in the sleeve 19of the brush carriage frame. The channel member II4 serves the samepurpose in connection with the brush carriage of a second Switch of thesame switch unit.

When the brush carriage is moved in either direction by the tape beltattached to ears l6 and ii, the sled of the brush carriage is heldfirmly against the ends of the rows of bank terminals by the engagementof the roller III with the inner face of channel member H3 and is guidedalong the rows of terminals by the ribs 65 and 66 of shoe E32 and theribs 68 and 69 of shoe 53. Should there be any vibratory movement of theface of the bank or of the channel member I i3 toward or away from eachother, the brush carriage will, due to the tension of spring I01, be soheld against'the face of the bank that there will be no tendency for i.In a selector switch, a terminal bank having rows of terminals, saidrows of terminals being grouped to form rows of terminal sets, a brush crriage associated with a row of terminal sets comprising a sled ofinsulating material engageable against the ends of said terminals andhaving portions extending therefrom between the rows of terminalsserving to guide said sled in its movement along a row of terminal sets,brushes resiliently secured to said sled for engagement with saidterminals, and means for resiliently holding said sled against the endsof said terminals.

2. In a selector switch, a terminal bank having rows of terminals, saidrows of terminals being grouped to form rows of terminal sets, a brushcarriage associated With a row of terminal sets comprising a sled ofinsulating material having a shoe on each end thereof engageable againstthe ends of said terminals, each shoe being provided with parallel ribsextending therefrom for engagement between the rows of terminals toguide said shoe in its movement along a row of terminal sets,

- brushes resiliently secured to said sled for engagement with saidterminals, and means for resiliently holding the shoes of said sledagainst the ends of said terminals.

3. In a selector switch, a terminal bank having rows of terminals, saidrows of terminals being grouped to form rows of terminal sets, a brushcarriage associated with a row of terminal sets comprising a sled ofinsulating material having a shoe on each end thereof, each shoe havinga convex surface slidably engageable against the ends of said terminalsand parallelly disposed ribs extending therefrom for engagement betweenthe rows of terminals to guide said shoe in its movement along a row ofterminal sets, brushes resiliently secured to said sled for engagementwith of said terminals and parallelly disposed ribs extending therefromhaving outer convex surfaces engageable with the inner edges of theterminals of the outer rows of terminals for guiding said shoev in itsmovement along a row of terminal sets, brushes resiliently secured tosaid sled for engagement withisaid terminals, and means forresilientlyholding the shoes of said sled against the ends of saidterminals.

5. In a selector switch, a terminal bank having rows of terminals, saidrows of terminals being grouped to form rows of terminal sets eachcomprising three or more terminals, a brush carriage associated with arow of terminal sets comprising a sled of insulating material having ashoe on each end thereof, each shoe having a convex surface slidablyengageable against the ends of said terminals and parallelly disposedribs extending therefrom between the inner and outer rows of terminalsofsaid terminal sets, out of engagement with the inner rows of terminalsand in slidable engagement with the inner edges of the terminals of theouter rows, brushes resiliently secured to said sled for engagement withsaid terminals, and means for resiliently holding the shoes of said sledagainst the ends of said terminals.

6. In a selector switch, a terminal bank having rows of terminals, saidrows of terminals being grouped to form rowsof terminal sets, a brush acarriage associated with a row of terminal sets comprising a sled ofinsulating material engageable against the ends of said terminals andhaving portions extending therefrom between the rows of terminalsserving to guide'said sled in its movement along a row of terminal sets,brushes resiliently secured to said sled for engagement with saidterminals, a member supported parallel to the face of said bank, andmeans resiliently secured to said sled and engaging said member to holdsaid sled against the ends of said terminals.

7. In a selector switch, a terminal bank having rows of terminals, saidrows of terminals being grouped to form rows of terminal sets, a brushcarriage associated with a row of terminal sets comprising a sled ofinsulating material engageable against the ends of said terminals andhaving portions extending therefrom between the rows of terminalsserving to guide said sled in its movement along a row of terminal sets,brushes resiliently secured to said sled for engagement with saidterminals, a member supported parallel to the face of said bank andsliders resiliently secured to said sled and engaging said member tohold said sled against the ends of said terminals.

8. In a selector switch, a terminal bank having rcwsof terminals, saidrows of terminals being grouped to form rows of terminal sets, a brushcarriage associated with a row of terminal sets comprising a sled ofinsulating material engageable against the ends of said terminals andhaving portions extending therefrom between the rows of terminalsserving to guide said sled in its movement along a row of terminal sets,brushes resiliently secured to said sled for engagement with saidterminals, a member supported parallel to the face of said bank and aroller resiliently secured to said sled and engaging said member to holdsaid sled against the ends of said terminals.

9. In a selector switch, a terminal bank having rows of terminals, saidrows of terminals being grouped to form rows of terminal sets, a brushcarriage associated with a row of terminal sets comprising a sled ofinsulating material engageable against the ends of said terminals andhaving portions extending therefrom between the rows of terminalsserving to guide said sled in its movement along a row of terminal sets,brushes resiliently secured to said sled for engagement with saidterminals, a member supported parallel to the face of said bank, andmeans for holding said sled against the ends of said terminalscomprising a U-shaped spring having one arm secured to said sled andhaving a roller rotatably mounted on the end of its other arm forengagement with said member.

10. In a selector switch, a terminal bank having rows of terminals, saidrows of terminals being grouped to form rows of terminal sets, a brushcarriage associated with a row of terminal sets comprising a sled ofinsulating material having a shoe on each end thereof engageable againstthe ends of said terminals, each shoe having parallel ribs extendingtherefrom for engagement between rows of terminals to guide said shoe inits movement along a row of terminal sets, a pair of brush springsmounted on each side face of one of said shoes extending parallel tosaid sled and having contact shoes on their free ends, said springsbeing flexible in a direction at right angles to their planes wherebytheir contact shoes are forced into engagement with the edges of theterminals of said rows, and means for resiliently holding the shoes ofsaid sled against the ends of said terminals.

11. In a selector switch, a terminal bank having rows of terminals, saidrows of terminals being grouped to form rows of terminal sets, a brushcarriage associated with a row of terminal sets comprising a sled ofinsulating material having portions extending therefrom between the rowsof terminals serving to guide said sled in its movement along a row ofterminal sets, brushes resiliently secured to said sled, certain of saidbrushes engaging the edges of the terminals of certain rows and other ofsaid brushes engaging the ends of the terminals of other rows, and meansfor resiliently holding said sled against the ends of said terminals.

12. In a selector switch, a terminal bank having rows of terminals, saidrows of terminals being grouped to form rows of terminal sets, a brushcarriage associated with a row of terminal sets comprising a sled ofinsulating material having a shoe on each end thereof engageable againstthe ends of said terminals, each shoe having parallel ribs extendingtherefrom for engagement between roWs of terminals to guide said shoe inits movement along a row of terminal sets, a pair of brush springshaving contact shoes thereon mounted on each side face of said sledbetween said shoes, the inner ones of said springs being flexible in adirection at right angles to their planes whereby their contact shoesare forced ino engagement with the edges of the inner rows of terminalsand the outer ones of said springs being flexible in a directionperpendicular to the face of said bank whereby their brush shoes areforced into engagement with the ends of the terminals of the outer rowsof terminals, and means for resiliently holding the shoes of said sledagainst the ends of said terminals.

13. In a selector switch, a terminal bank having rows of terminals, saidrows of terminals being grouped to form rows of terminal sets, a brushcarriage associated with a row of terminal sets comprising an insulatingsupport and a pair of brush springs mounted on each side face of saidsupport, the inner ones of said springs each comprising a frame having arear member attached to said support, laterally extending end membersrigid in the direction of travel of said brush carriage, but flexible ina direction at right angles to its plane and a front member having acontact shoe attached thereto whereby the contact shoes of said innersprings are held in engagement with the edges of the inner rows ofterminals and the outer ones of said springs comprising a rigid bodyportion attached to said support and an arm extending from the endthereof disposed to have flexibility in a direction perpendicular to theface of said bank and having a contact shoe on the end thereof wherebythe contact shoes of said outer springs are held in engagement with theends of the outer rows of terminals.

14. In a selector switch, a terminal bank having rows of terminals, saidrows of terminals being grouped to form rows of terminal sets, a brushcarriage associated with a row of terminal sets comprising a sled ofinsulating material engageable against the ends of said terminals andhaving ribs extending therefrom between the rows of terminals serving toguide said sled in its movement along a row of terminal sets, brushesresiliently secured to said sled for engagement with said terminals, aU-shaped frame secured by its inner arm to said sled and having a sleeveon its outer arm in which a cable of flexible conductors may be secured,a member supported parallel to the face of said bank and positionedbetween the arms of said frame, a spring secured to the inner arm ofsaid frame and a slider secured to each end of said spring for engagingthe inner face of said member to hold said sled against the ends of saidterminals.

CLARENCE N. HICKMAN.

